1. Field of the Invention
The present invention is related to the field of pile anchor foundations and, more particularly, to a post-tensioned pile anchor foundation including a post-tensioned foundation cap and a plurality of post-tensioned pile anchors extending vertically downward therefrom and a method of constructing such a post-tensioned pile anchor foundation.
2. Description of the Related Art
In a normal pile foundation, the piles extend to or into the above concrete foundation and are only compression resisting foundation extensions. Such pile foundations are not post-tensioned.
When tall, heavy and/or large structures are constructed, a post-tensioned concrete foundation is desirable in order to provide improved rotational stiffness, minimized movement from dynamic forces, and increased foundation frequency to approach the frequency of a rigid body. Such concrete foundations are particularly useful for the support of tall, heavy and/or large towers which may be used to support wind turbines, power lines, street lighting and signals, bridge supports, commercial signs, freeway signs, ski lifts and the like.
Various different forms of concrete foundations utilizing post-tensioned reinforcement and operational features of the instant invention have heretofore been disclosed in my earlier U.S. Pat. Nos. 5,586,417, 5,826,387 and 6,672,032, the disclosures of which are expressly incorporated herein in this application by reference as if fully set forth in their entirety. However, the concrete foundations of my aforesaid patents do not relate to pile anchor foundations. Therefore, a need exists for a pile anchor foundation that allows for the pile anchors to be post-tensioned.